© 2011-2017 Evince Technology Limited, Netpark, Sedgefield, County Durham, UK, TS21 3FD
While there have been some significant advances in the manufacture of electronics over the past 60 years, since the invention of the MOSFET there has been little or no fundamental advancement in semiconductor devices since that time. As silicon comes ever closer to it physical limits, candidate replacement materials such as silicon carbide and gallium nitride have so far to make any significant inroads as its replacement. There are several reasons for this but at the top of the list is the notion that whatever people try, they remain mired in trying to replicate silicon device concepts in new materials. The result is newer, better but significantly more expensive mousetraps that ultimately have the same basic flaws and weaknesses of the silicon devices they seek to usurp.
A small but growing number of people are realising that the only way forward is to break the classical silicon paradigm and look at fundamental new ways of making devices. While graphene and other 2D compounds have caused a lot of excitement it is not the only way to crack the problem. Another way is to look once more at pure electron devices – which are inherently extremely fast, capable of scaling to handle power levels from nano-watts to megawatts and, able to operate over a far wider range of environmental parameters than presently possible.
Evince is developing a new family of completely solid-state devices (look no vacuum!) that at their heart contain electron emission sources fully embedded within a diamond substrate. The family includes:
Because they are based on diamond all of these devices will inherently offer high voltage, high current and high frequency capabilities with a robustness that cannot be matched by any other semiconductor technology. Also while other wide bandgap materials are often touted as being suitable for high temperature performance, only diamond has the necessary combination of electrical and thermo-mechanical properties needed to make devices able to operate up to 400C.
It's now widely acknowledged that for concepts such as electricity smart grids and the industrial internet cannot be fully realised until a key missing component in the jigsaw becomes available. This is the availability of power electronic devices able to operate reliably and able to cope with system fluctuations at voltages of 10,000V and above. Diamond can inherently operate at these power levels and the approach used by Evince offers the prospect of robust devices that can limit faults through saturation.
Extreme Environment Devices
As the frontiers of technology are pushed ever outwards the conditions that electronic systems are required to operate in is getting more extreme. Industries such as oil and gas, aerospace, nuclear, defence and even automotive are increasingly seeking devices able to reliably operate at up 400C and potentially under radiation exposure. The approach we have taken is based on a physical principle and therefore largely independent of temperature. Diamond is also one of the most radiation hard materials going.
Ultra-High Frequency Devices
Vacuum electron devices made using semiconductor techniques at the microelectronic scale have been shown to operate at frequencies in the 100's of GHz but suffer from short lifetimes. Our approach delivers this completely within the solid-state avoiding the degradation mechanisms that vacuum suffer from and benefits from the thermo-electric performance that diamond can offer. Creation of devices able to exploit the THz spectrum open up possibilities across a whole range of applications. including spectroscopy, medical imaging, defence and security systems.
Despite decades of advancement in processor design, Moore's Law has been broken since 2005 when clock speeds stalled. With feature sizes of 20nm soon to be rolled out at a cost of more to produce than the previous generation, the law of diminishing returns has surely been reached. The original computers were all based on vacuum tubes, however with the approach taken by Evince it's now possible to shrink a single valve down to less than a micron in size in one of the most thermally conductive materials known to man.